(NaturalNews) In a laboratory environment, scientists have learned how to create, delete and restore memories. The subjects are currently rats. Researchers are considering the following results to be a major breakthrough.
In a recent study conducted by researchers at the University of California's San Diego School of Medicine, a team of researchers successfully erased memories in rats. They were then able to reactivate those same memories, altering the animal's response to past events in the process.
The study was published in the online issue of the scientific journal Nature and is the first to confirm that memories can be selectively erased and then predictably reactivated.
This is accomplished by stimulating groups of nerves in the brain at certain frequencies in order to strengthen or weaken the synapses. According to senior study author Roberto Malinow, MD, PhD, professor of neuroscience, this allowed researchers to form a memory, erase it, and then reactivate the same memory.
In this case, a group of nerves in the rat's brain was genetically modified to be more sensitive to light and then optically stimulated. At the same time, an electric shock was given to the rat's foot. The animals quickly began to associate the optical stimulation with pain and reacted fearfully whenever the nerves were stimulated. An analysis conducted during this portion of the study showed that the stimulated nerve synapses exhibited chemical changes that indicated synaptic strengthening.
During the next stage of the study, researchers were able to weaken this effect by stimulating the same genetically modified group of nerves with a low-frequency train of optical pulses. This was successful in erasing the memory. Researchers could judge the success of this portion of the study by observing the rats, who no longer responded fearfully to optical stimulation.
Scientists then restimulated the same nerves, this time with a high-frequency train of optical pulses. Once this was done, the rats would again respond to the original optical stimulation with fear, even though their feet were not being shocked.
Manilow claims that these results could lead to the next advances in Alzheimer's disease treatment. Because the weakened rat synapses could be reversed, it may be possible to counteract the effects of beta amyloid in patients with the disease. It is this compound that causes the weakened synaptic connections that cause an Alzheimer's patient's memory to fade.